Gas separator

Beginning of the patent period: 15 November 1965.

The invention relates to a submersible gas separator unit having a cylindrical housing, a drive shaft for connection to a motor and a pump, a bottom closure, a plurality of adjacent to the upper part of the Separatorgehäuses inlet openings, a vertical Htllse which coaxially and radially in Separatorgehäuse inwardly spaced apart and for the

Pump forms an intake, wherein the lower part of the Separatorgehäuses forms a memory for the pump, and a Separatorpumpe.

In a motorized submersible pump device, it is common practice to provide an electric motor for driving the pump and to interpose between them a seal and a gas separator, all of which are driven by a shaft rotated by the common motor, the pump at the top End of the group is arranged and the connecting drive shaft extends through the sealing portion of the separator. Sometimes the gasket and the engine may be one piece, but more often each is a separate part which is carried by the pump through the shaft passing through it and through the gas separator.

In the oil or water wells into which the submergible motor-pump device is immersed, free and entrained gas occurs adjacent to the pumped liquid which impairs the performance of the pump with respect to the expected pumping volume. In many cases, this degradation by the gas only causes a considerable reduction in the volumetric or mechanical degree of efficiency of the pump, in other cases, however, the gas causes the production to be suspended.

Numerous attempts have been made to overcome the problem of suspension of the delivery, such as by providing special controls which, in the event of gas lock, automatically shut down the pump for sufficient time to allow the gas to flow out and then automatically turn it on again. This is of course unsatisfactory due to the necessary control devices and as a result of the low pumping speeds and the resulting low-end 25 low efficiency.

Further attempts which have been made involved pressurizing components at the pump inlet by providing in the separator a second pump impeller which provides fluid supply to the pump inlet and separates a portion of the free or entrained gas prior to reaching the pump inlet. In a known device for gas separation on a Mo30 continuous suction pump, the gas separation is carried out by a Axiallaufrad. It has been found, however, that these prior art separators themselves form a gas barrier at their impeller inlet which is as severe as the exposure to gas barrier inhibition in the pump itself. Such gas blocking may occur in the prior art inlet inlet of the lower impeller as this inlet is points down so that entrained in the liquid gas or gas bubbles can easily enter the intake or form a large gas bubble below it.

Accordingly, it is an object of the invention to provide a gas separator for a submersible pump which overcomes the difficulties of the prior art gas separators.

It has been found that it is far more favorable to direct the separator inlet upwards and the

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Redirect flow during and after the impeller, so that gas bubbles can be removed before by the natural buoyancy.

The submersible gas separator unit according to the invention therefore has the feature that the separator pump has a radial impeller in a diverter housing, which housing has an inlet communicating with the reservoir and directed towards the inlet openings, and an outlet connected to the sleeve. so that the radial impeller drives fluid from the inlet into the vertical sleeve, wherein the flow direction of the liquid is reversed.

As a result of the upward inlet to the radial impeller, gas which may be formed at the inlet of the pump may flow back through the liquid to the reservoir. in case of a

Gas ingress or a so-called pumped-off condition, the upstream inlet prevents continued gas obstruction or blistering, which would ordinarily form under these circumstances, thus preventing liquid from flowing into the pump due to gravity in the presence of fluid.

Otherwise described arrangement, a liquid flows after the upward flow on the Außen15 side of the housing on the inside of the housing back down. This flow reversal already removes some of the gas from the housing. When the liquid reaches the upstream inlet and is forced upwardly by the separator cycle bath, it reverses its direction of flow, again reducing the amount of gas entering the pump inlet.

Other features of the invention relate to the formation of the flow paths in the form of at Rad20 rad in the gas separator adjacent passages for the return of the gas-liquid mixtures, which may be pressed by the weight of the liquid in the Flieggebad, so as to increase the volumetric efficiency of this pump impeller and Further, the arrangement of openings which are adjacent to the pump wheels of the pump itself, so as to remove the gas therefrom; this latter feature serves to ensure flow in the presence of liquid after a gas collapse or a pumped-off condition.

The invention wbd explained in more detail below with reference to the drawings.

In the drawings: Fig. 1 is a sectional side view showing the extended gas separator operation immersed in connection with the pump unit and the motor unit in a well casing; FIG. 2 shows a cross section along the line 2-2 of FIG. 1 in the direction of the arrows; FIG.

Fig. 3 is an enlarged cross-section along the line 3-3 in the direction of the arrows.

In the drawings, the gas separator constructed in accordance with the principles of the invention is designated in its entirety by 10 and is shown in its arrangement in a well housing 11. The gas separator 10 is shown coaxially between a multistage submersible centrifugal pump, shown soft-gauge, but designated in its entirety by 12, an immersion seal 13 and 35 an intermediate submersible motor 14; These latter two units are shown only schematically. The pump circuit baths 15 are driven by the motor 14 through a coaxial shaft 16 which extends through the seal 13 and the gas separator. Grooves 17 in the shaft serve to establish the coupling of the individual shaft sections between pump and motor.

The gas separator 10 is provided with an outer cylindrical casing 18 which is provided so as to be spaced from the well casing 11 at the lower end and closed at the lower end by a bottom part 20 and at the upper end by a ceiling part 21, and thus an outer chamber 22 forms. In the embodiment shown, the bottom part 20 is provided with a flange 23, which serves in the usual way for connecting the gas separator by flanging on the seal and the cover part 21 is provided with an external thread 24 which engages in the internal thread 25 of the pump housing 26 and so creates a connection between Separatorgehäuse and pump housing. In this assembly thus forms the Gasseparatorgebäuse a part of the pump housing and in turn carries the seal 13 and the motor 14th

In the radial inward direction of the inner wall of the outer housing 18 is a second inner vertical cylindrical housing or sleeve 27, which is coaxial with the shaft 16 50 and spaced from and from the shaft sleeve 28, both form an intake manifold 30. The shaft sleeve 28 abuts against the shaft, whereas the sleeve 27 is inserted into the cover part 21 and represents via the bore 32 the connection to the inlet 31 of the pump. A plurality of centering bearings 33 (one shown, Fig. 1,3) are used to support the sleeve 27 and are provided with openings 34 for the passage of the liquid.

At the lower end of the sleeve 27, a separator pump is provided which is designated in its entirety by 35 and has a deflection housing 36. This bender is with the Sepa3

No. 248,254, which are directed upwards, such that they open into the outer chamber 22. As can be seen, passes through a plurality of radially inwardly and downwardly directed openings 39 in the outer housing 18 into the inner chamber 22 entering liquid in the deflection housing 36 and from there into the opening 40, from where they are in a conventional

Pumping is promoted by the centrifugal impeller 41 radially outward and through the outlet conduit 42 and from there up through the intake manifold 30 to the Pumpenkreiselrad inlet 32 ​​passes. The liquid flowing in through the outer chamber thus reverses its flow direction in the separator deflecting housing and is pumped into the pump inlet 31 by the action of the gas separator pump impeller 41.

When the pump 12 is driven by the motor 14, the conveyor flows upward in the well, the conveyor, as mentioned above, usually being a mixture of liquid and free and absorbed gas and affecting the pumping capacity of the pump. Thus, the conveyance flowing upward in the well chute to the gas separator is forced to reverse direction upon entering the plurality of inward and downward openings 39. This directional turn already causes some of the gas to be eliminated.

The housing inlet openings 39 are arranged in the upper part of the housing, so that the underlying part of the housing forms a memory. If this is filled with liquid, a part of the free and adsorbed gas can rise due to the buoyancy and escape through the uppermost inlet openings.

During continued operation of the separator, the gas in the reservoir may form a gas bladder adjacent the impeller inlet 38 of the gas separator. However, this bubble will rise with increasing size due to the upward opening of the inlet 38 through the liquid in the reservoir and, if appropriate, make its way through the top of the housing openings 39 to the outside. The force of gravity on the liquid in the reservoir facilitates the removal of this gas bubble, so that no suspension of delivery occurs.

In the event that some gas enters the gas separator impeller 41 together with the liquid, the impeller forces this gas through the openings 45 into an annular chamber 44, from where it flows back through the passage 46 into the well liquid.

Of course, if a gas collapse occurs, the liquid supply to the separator pump will dry up, but if the reservoir fills with liquid again, the action of gravity on this liquid will eliminate any possible formation of a gas pocket in the inlet 38. As a result of gravity, the liquid is forced by itself into the inlet, the pump is able to automatically put the intake 30 again under pressure and the fluid to the pump 12 to press.

Should the gas breakdown persist until an excessive decrease in the amount of liquid in the separator is effected, ie in the case of dry running of the intake nozzle 30, then after resumption of the liquid delivery by the gas separator impeller means for deriving any gas pocket formed in the inner chamber provided so that the liquid can flow to the pump impellers. This is in the embodiment shown by an annular

Chamber 46 'accomplished in the pump housing below the Pumpenkreiselrades 15, which is in communication with the liquid in the well housing via a arranged in the ceiling part 21 passage 47 with a small cross-section. This chamber 46 'communicates with the liquid in the pump rotor gears via the annular gap 48 between the impeller and pump housing in constant communication. When oil is being pumped, there is often sand in the liquid, which flows with the oil and enters the outer chamber 22 and from there passes with the liquid to the gas separator pump 35. A device in the form of an annular chamber 48 ', which communicates with the impeller Uber the annular gap 49 between the outer periphery of the impeller 41 and the housing in connection collects due to the deflection of the liquid flow in the vicinity of the annular gap this sand and lei tet him to the well back through the passage 50.

In the illustrated embodiment, the bottom portion 20 is also provided with a passage 51 which connects the chamber 52 with the liquid in the well. This chamber 52 with its connection to the outside serves to prevent the occurrence of excessive pressure by any excess liquid flowing after the first storage 53 or due to a possible expansion of the liquid in the seal 13 or motor 14.

Whether or not the invention has been described for use in conjunction with a separate seal 13 and a separate motor 14 (preferably, the seal is of the type described in U.S. Pat.

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Patent No. 246850 described and the motor preferably from the in the French. Patent

No. 1,314,268), it may of course also be used with any separate seal and motor, or with a motor whose seal is an integral part, but may also be used as an integral part of the pump.